24 lines
522 B
C
24 lines
522 B
C
// SPDX-License-Identifier: GPL-2.0
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#include <linux/bpf.h>
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#include <bpf/bpf_helpers.h>
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struct {
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__uint(type, BPF_MAP_TYPE_CGROUP_STORAGE);
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__type(key, struct bpf_cgroup_storage_key);
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__type(value, __u64);
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} cgroup_storage SEC(".maps");
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SEC("cgroup_skb/egress")
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int bpf_prog(struct __sk_buff *skb)
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{
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__u64 *counter;
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counter = bpf_get_local_storage(&cgroup_storage, 0);
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__sync_fetch_and_add(counter, 1);
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/* Drop one out of every two packets */
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return (*counter & 1);
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}
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char _license[] SEC("license") = "GPL";
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